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CHARLES HL STROUD, 0F MINNEAPOLIS, MINNESOTA, ASSIGNGR OF ClE-HLF T0 ROLLIN E. STARKEY, OIF MNNEAYLIS, MINNESOTA..

SEARK-LUG.

Application filed December 1, 1916.

To all whom it may Coni-ern.'

Be it known that I, CHARLES ll/, STROUD, a citizen of the United States, residing at Minneapolis, in the county of Hennepin and State et illinnesota, have invented certain new and useful Improvements in Spark- Plugs; and I do hereby declare the folle ringr to be a full, clear, and eXaot deseription or" the invention, s ueh as will enable others skilled in the art to which it appertains to inale and use the sa me.

lffiy invention relates to spark plugs for i and provides :in iiiiliiroved for drawing an auxiliary eliarge,

oi oarbureted air, axially tliroi the plug; and against the electrodes, herr iy keeping the latter clean of carbon and inexplosive engi: -i:- ineans crea-sing the efficiency olf the explosion.

In accordance with the invention, the spark plug is provided with an axial metal tube, the lower or inner end oi Wliieli is preferably utilized one of the eleetrodes; and Within this axial tube, is `a olieclvalif'e that perni-its an iiiioiv of vapor under 'the suction stroke of 'the piston, butelieels a reverse flou' under the. force of the ex'ilosion. This valve is yieldingl .losed by a `coiled spring' that .is protected from 'the intense heat roni the explosions, by the valve headI or ball and valve seat, both of which are located inward of the said spring. The sleeie like plug body is provided With. an electrode that cooperates ivi-th the end of the axial tube to afford the tivo electrodes of the plug; and the head or' the valve located immediately over and so closely adjacent to these electrodes that it will, when the valve is drawn into an open position, serve as a. deflecter to throw the hydro-carbon vvapor over the entire surface of both electrodes.

The outer eiid oi the axial tube of the plug is connected to the vapor intake inanifold of the engine.

.lin the accompanying drawings which illustrate the invention, like characters indi Cate like parts throughout the several vieu/s.

Referri iig to the drawings Figure 1 is a plan View showing four plugs applied to a four-cylinder engine;

Fig. 2 is a side elevation of the improved plug; and

Fig. is a vertiealseetion taken centrally thereof.

The iiuiiieial l indicates the oyliiider or cylinder casting, the numeral 2 the vapor Speeicaton of Letters Patent.

Patented July 22, 1919. saranno. 134,337.

intake manifold, and the numeral 3 the carburetor ot' an ordinary foureyliiider eX- plosive engine. The sparking plug proper comprises a metallic sleeve-like plugr body l adapted` to 'oe screwed iii the usual Way into the head of il'ritliin the plug 5 that is seated therein with a packed and held by means of an ordinary gland l5.

Extended axially through the core 5 is the 'tallie vapor conducting tube 'T that proi through said plug at both ends, and s lower portion is provided with a collar iioivn as seated in a recess t'oiiiied in the loii'erendof saidcore. Tlieiippereiuil oi' the tube 'i' is threaded and provided with a uut i) between which and the upper end oi tl i core, the packing l() and a serond nut 1l are interposed. The nut 9 also serves to connect to the outer end of the tube 7, one end of an elbow 12, the other end which. elbow is connected by a short rubber hose 13 and a pipe 13 to the Vvapor intake manifold 5 ot' the engine. 0f course, for a inulti-oylinder engine, the pipe 13 will have branches leading' to the elbows oit' the several plugs.

rl`lie short. hose sections 13a not only ait'ord elieaii couplings, but the?.y serve as insulii-v tioiis vi'roiii being l`ground through the engine. The electric wire leading to the plug iiiay be conif'eiiioiitly applied to the grooved head of a. plug' 12a, which, as shown, is screwed into the top of This plug- 12a,

the VeoiLieratiiig cylinder. body d is a porcelain Core Joint the elbow when removed, furtlieiiiiore, to the interior of the tube 7, and, coiisequeiitly, to the nut 17 of the stein, 1G.

.l short distance above its lower end, the axial tube 7 has a contracted valve seat 14. against which is normally seated the `head of a cheek valve 1:3. The head of this cheek valve is preferably spherical, and it is -provided with a long stein 1G that extends through the valve seat and outward iii the tube 7. and at its outer end is provided with au adjustable iiut 17. AA. coiled spring 18 surrounds the valve stein 16 and is oompi'essed between the back of the valve seat 1l and the nut Shis spring, of course, normally holds the cheek valve closed.

Under the suction stroke of the engine, which, of course, draws the inain charge of vapor into thecylinder through the oustoniaiy intake port, an auxiliary charge of lo prevent the electro-torniiiig tube 7 i a fi'ords accessy vaL or will also be drawn into the4 cylinder 110 through the axial tube 7. lVhen the cheek vulve 15 is drawn into its open position by suction, :is stated, the hydrocerhon Vapor drawn through said tube (will be sprayed all :Lround the lower' end oi' eairl tube, tovwn, around that portion thereof hot serves es one of the electrodes, and will also he sprayed over the other eleetrolle 19, which, us shown, is in the form of e smell metallic linger rig; idly attached to the lower end of the plug body l. Thus, the electrodes are Washed with the hydrocarbon vapor and kept elem: of Carbon, andv moreover, the efficiency of the explosion s increased by 'ellis auxiliary charge of Vapor.

The spring being outward of the vulve heed, its seat is protected 'from the intense heut from explosions and, furtherniore7 is kept cool by the stream of vapor drawn in through the intake tube. This arrangement of the spring, in respect Jaio the vulve heed and seat, is of the greatest inuportunge, hecause in practice it has been found that where u spring is exposed to 'the direct heet from. the explosion, its temper will soon be drawn und the spring rendered useless., lSo, the proximity of the vulve heed to the' electrode el the plug, whereby the letter ere Well sprayed with the vapor, is of very greet Importance.

,The plug described is olsimple construclemme tion and may be mede of small cost. .lts elliheen (lenumstreefl in practice. What l Glenn is:

A operi( plug Comprising u holly7 nu inr suleting eore therefor, e. lwllo'w' iis-el ruhe extenfng through the core end serving en electrode, the lower emi of Seial lube heing open, :L grounded electrode located heneath the open end of the tube, e valve arranged in the tube slight disenee above the lower enal thereof und urrengerl, when open, to @euse e spraying of the-fuel the Yell of the tube, u vulveeteni @n iujiu'ewlly hrough the 'fuel tuleI en@ e cloising spring for the valve encircling the stein and, :wronged within the Luhe, Sher-e aseing un annuler space between Jthe stern und 'lle well of the tube, whereby the fuel will he conveyed to ull eirles of the relire, i being arranged to diront the fuel against the grounderl electrode and against, portion of the tube which nel@ e Second electrode, whereby the electrodes free from carbon.

ln testimony 'ehi-freer l of. i: my signzieure in presence of two Witnesses.

Well f ere kept 

